Method and apparatus for multiple input power distribution to adjacent outputs

ABSTRACT

Methods, systems, and apparatuses provide power from multiple input power sources to adjacent outputs efficiently and reliably. Aspects of the disclosure provide a power distribution unit (PDU) that includes a number of power outputs including first and second adjacent power outputs. The PDU includes a printed circuit board having a first conducting layer electrically interconnected to a first power input connection and the first power output, a second conducting layer that is at least partially above the first conducting layer and in facing relationship thereto. The second conducting layer is electrically insulated from the first conducting layer and electrically interconnected with a second power input connection and the second power output, the first and second power outputs thereby connected to different power inputs.

FIELD

The present disclosure is directed to devices, systems and methods usedin power distribution, power management, and power monitoringapplications. More particularly, the present disclosure is directed todevices, systems and methods having the capability to provide adjacentoutputs power from different power inputs.

BACKGROUND

Power distribution units have long been utilized to supply power toelectronic equipment. A conventional power-distribution unit (PDU) is anassembly of multiple electrical “outlets” (also called “receptacles” or“outputs”) that receive electrical power from a source and distributethe electrical power via the outlets to one or more separate electronicequipment units having respective power cords plugged into respectiveoutlets of the PDU. In some applications, a PDU receives power from twodifferent power inputs, commonly referred to as “dual feed” or “dualinput” PDUs. Such dual inputs can provide additional power supplycapability to a PDU, and/or may provide redundant sources of power forequipment that receives power from PDU outlets. PDUs can be used in anyof various applications and settings such as, for example, in or onelectronic equipment racks (such as RETMA racks) to provide power tonetwork devices (e.g., servers, routers, gateways, network switches),among other applications. One or more PDUs located in a cabinet may forconvenience be referred to as a Cabinet Power Distribution Unit (CDU).

Power distributed to small businesses or residential customers iscommonly “single phase” or “dual phase” power. In a single phase system,a single alternating current with a sinusoidal voltage is distributedthrough a two-line connection. In a split phase system, two alternatingvoltages are distributed through at least three lines: one neutral lineand one other line for each of the two phases. The two voltage waveformsvoltages are separated in time by a “phase difference” of 180degrees—that is, the sinusoidal form of the voltage on one line leads orlags the sinusoidal form of the voltage on the other line by the amountof the phase differential. The effective voltage between the first phaseline and the second phase line is therefore significantly greater thanthe effective voltage between each of the phase lines and the neutralline. As a result, a three-line, split-phase system may provide, forexample, 120 volts in a phase-to-neutral line circuit and 240 volts in aphase-to-phase line circuit.

In larger commercial and industrial applications, three phase systemsmay be employed. In three phase systems, each voltage cycle on eachphase line is 120 degrees, or ⅓ of a period, out of phase with thevoltage cycle on each of the other two phase lines. Three phase systemsare used in large commercial and industrial applications becausethree-phase equipment is smaller in size, weighs less, and is moreefficient than single or dual phase equipment. Although three phasecircuits are somewhat more complex than single or dual phase circuits,they weigh less than single phase circuitry for the same loads supportedby the circuitry. Three phase circuits also can provide a wide range ofvoltages and can be used for single or dual phase loads.

Three phase power is generated by circuits in either of twoconfigurations: (i) a “delta”; or (ii) a “wye” configuration. If one endof each of the legs of a three-phase circuit is centrally connected at acommon point and the other ends are connected to three phase lines (oneline for each phase), the configuration is called a wye or “Y”connection. If the legs of the three phase circuits are connectedinstead in series to form a closed loop, with one phase line connectedto each junction of two adjacent legs, the configuration is called adelta or “Δ” connection.

One reason that three phase circuits are more complex than typicalsingle phase circuits is the need to maintain at least somewhat balancedloads among each of the three phases. One indicator of imbalance is thelevel of current flowing through each phase line. If the level ofcurrent flowing through a phase line is significantly different thanthat flowing through a different phase line, the load is considered tobe unbalanced. In a wye connected system, imbalance can also beindicated by current flowing through the neutral line. Imbalance betweenthe loads can result in damage to the three phase system, can causeexcessive wear of components in the system such as the three-phasegenerator, can result in increased power usage, and can be difficult andcostly to correct.

For example, high capacity data centers used in computer andcommunications network applications commonly utilize three-phase powerfor provide operating power to equipment located in hundreds orthousands of equipment racks within the data center. Commonly,three-phase power is supplied to the equipment racks via a four or fiveline input, providing a line for each voltage phase, an earth ground,and a neutral line for three-phase wye connections. A vertically, orhorizontally, oriented power distribution unit connects to the input anddistributes power of differing phases to a plurality of outputs for thephase. A three-phase PDU typically provides three or more branches ofoutputs, one branch for each phase of power provided by the three-phaseplug strip. The PDU can be mountable on or adjacent to a given equipmentrack in order to supply three or more branches single phase power (witheach such branch derived from the three-phase power input) to the rackor other equipment in the vicinity.

SUMMARY

In various embodiments, a power distribution unit (PDU) is provided thatcomprises (a) a PDU housing; (b) a power input disposed at leastpartially within the housing comprising at least a first inputconnection electrically connectable to a first power source, and asecond input connection electrically connectable to a second powersource; (c) a plurality of power outputs disposed at least partiallywithin the housing comprising at least a first power output and a secondpower output located adjacent to the first power output; and (d) aprinted circuit board disposed in the housing comprising (i) a firstconducting layer electrically interconnected to the first inputconnection and the first power output, and (ii) a second conductinglayer that is located at least partially above the first conductinglayer and in facing relationship thereto, electrically insulated fromthe first conducting layer, electrically interconnected with the secondinput connection, and electrically interconnected with the second poweroutput, the first and second power outputs thereby connected todifferent power inputs.

In some embodiments, the printed circuit board further comprises a firstconductively plated through hole extending through the first and secondconducting layers, with the first conductively plated through hole beingelectrically connected to the first conducting layer, electricallyinsulated from the second conducting layer, and electricallyinterconnected to the first power output. The printed circuit board ofsuch embodiments may further comprises a second conductively platedthrough hole extending through the first and second conducting layers,with the second conductively plated through hole electrically connectedto the second conducting layer, electrically insulated from the firstconducting layer, and electrically interconnected to the second poweroutput.

The power input may further include a third power input connectionelectrically connectable to a third power source, in which case thepower outputs include a third power output located adjacent to thesecond power output, and the printed circuit board further comprises athird conducting layer that is located at least partially above thefirst and second conducting layers, electrically insulated from thefirst and second conducting layers, electrically interconnected with thethird input connection, and electrically interconnected with the thirdpower output. With such a configuration the first, second, and thirdpower outputs are thereby connected to different power inputs. Theprinted circuit board may comprise (1) a first conductively platedthrough hole extending through the first, second, and third conductinglayers and being electrically connected to the first conducting layer,electrically insulated from the second and third conducting layers, andelectrically interconnected to the first power output; (2) a secondconductively plated through hole extending through the first, second,and third conducting layers and being electrically connected to thesecond conducting layer, electrically insulated from the first and thirdconducting layers, and electrically interconnected to the second poweroutput; and (3) a third conductively plated through hole extendingthrough the first, second, and third conducting layers and beingelectrically connected to the third conducting layer, electricallyinsulated from the first and second conducting layers, and electricallyinterconnected to the third power output.

In some embodiments, the power outputs comprise at least first andsecond groups of linearly arranged power outputs, adjacent outputswithin each of the groups being interconnected to different powerinputs. The PDU, in some embodiments, also includes a plurality of powercontrol relays disposed in the housing, each among the plurality ofpower control relays being connected in independent power controllingcommunication between the power input and one of the power outputs. ThePDU may also include a current-related information reporting system(e.g., at least one of current, voltage and power) disposed in thehousing in current-related information determining communication withone or more of the power input and power outputs, and connectable incurrent-related information transfer communication with a separatecommunications network distal from the power distribution apparatus.

The power input to the PDU may comprise a first power input connected toa first power source and a second power input connected to a secondpower source, or may comprise a three phase power input where the firstand second power sources correspond to different phases of the threephase power input.

Another aspect of the disclosure provides a printed circuit boardapparatus for providing adjacent power outputs with power from differentpower inputs, comprising: (a) a first conducting layer comprising afirst input connection configured to be connected to a first power inputand a first output connection configured to be connected to a firstpower output; and (b) a second conducting layer located at leastpartially above the first conducting layer, preferably in facingrelationship thereto, and electrically insulated from the firstconducting layer. The second conducting layer comprises a second inputconnection configured to be connected to a second power input and asecond output connection configured to be connected to a second poweroutput.

The printed circuit board may include a first conductively platedthrough hole that extends through the first and second conducting layersand is electrically connected to the first conducting layer, andelectrically insulated from the second conducting layer, and a secondconductively plated through hole that extends through the first andsecond conducting layers and is electrically connected to the secondconducting layer, and electrically insulated from the first conductinglayer.

The printed circuit board may also include a third conducting layerlocated at least partially above the first and second conducting layers,and preferably in facing relationship thereto. The third layer iselectrically insulated from the first and second conducting layers andcomprises a third input connection configured to be connected to a thirdpower input, and a third output connection configured to be connected toa third power output. In such embodiments, a first conductively platedthrough hole may extend through the first, second, and third conductinglayers, be electrically connected to the first conducting layer,electrically insulated from the second and third conducting layers, andelectrically interconnected to the first power output connection; asecond conductively plated through hole may extend through the first,second, and third conducting layers, be electrically connected to thesecond conducting layer, electrically insulated from the first and thirdconducting layers, and electrically interconnected to the second poweroutput connection; and a third conductively plated through hole mayextend through the first, second, and third conducting layers, beelectrically connected to the third conducting layer, electricallyinsulated from the first and second conducting layers, and electricallyinterconnected to the third power output connection.

Another aspect of the disclosure provides a method for providing powerto adjacent power outputs from different power inputs in a powerdistribution unit, comprising: (a) connecting a first conducting layerof a printed circuit board to a first power input; (b) connecting asecond conducting layer of the printed circuit board to a second powerinput, with the second conducting layer located at least partially abovethe first conducting layer and electrically insulated from the firstconducting layer; (c) connecting a line power connection of a firstpower output to the first conducting layer; and (d) connecting a linepower connection of a second power output adjacent to the first poweroutput to the second conducting layer.

The method may also include connecting a third conducting layer of theprinted circuit board to a third power input, with the third conductinglayer located at least partially above the first and second conductinglayers and electrically insulated from the first and second conductinglayers; and connecting a line power connection of a third power outputthat is adjacent to one of the first and second power outputs to thethird conducting layer.

Connecting the line power connection of the first power output to thefirst conducting layer may include connecting a first conductivelyplated through hole to the line power connection of the first poweroutput, with the first conductively plated though hole extending throughthe first and second conducting layers, being electrically connected tothe first conducting layer, and being electrically insulated from thesecond conducting layer. Connecting the line power connection of thesecond power output to the second conducting layer may includeconnecting a second conductively plated through hole to the line powerconnection of the second power output, with the second conductivelyplated though hole extending through the first and second conductinglayers, being electrically connected to the second conducting layer, andbeing electrically insulated from the first conducting layer. The methodmay also include connecting a third conductively plated through hole tothe line power connection of a third power output, with the thirdconductively plated though hole extending through a third conductinglayer and the first and second conducting layers, and being electricallyconnected to the third conducting layer, and electrically insulated fromthe first and second conducting layers.

It is to be understood that the foregoing is a brief description ofvarious aspects of various embodiments. It is therefore also to beunderstood that the scope of the invention is to be determined by theclaims as issued and not by whether given subject matter includes any orall such features or advantages or addresses any or all of the issuesnoted herein.

In addition, there are other advantages and varying novel features andaspects of differing embodiments. The foregoing and other features andadvantages will become more apparent from the following detaileddescription, which proceeds with reference to the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

Several embodiments including the preferred embodiments and currentlyknown best mode of the present invention are shown in the followingdescription and accompanying drawings in which:

FIG. 1 is a front perspective view of a power distribution unit of anexemplary embodiment;

FIG. 2 is an illustration of a group of outputs and associated printedcircuit boards according to an exemplary embodiment;

FIG. 3 is an illustration of an output receptacle of an exemplaryembodiment;

FIG. 4 is an illustration of a printed circuit board that providesoutputs with power from different inputs according to an exemplaryembodiment;

FIG. 5 is an illustration of a printed circuit board that providesoutputs with power from different inputs according to another exemplaryembodiment;

FIG. 6 is a perspective view illustration, partially in cross section,of a printed circuit board that provides outputs with power fromdifferent inputs according to an exemplary embodiment;

FIG. 7 illustrates conducting material of a conducting layer of aprinted circuit board that provides outputs with power from one ofseveral power inputs according to an exemplary embodiment;

FIG. 8 illustrates conducting material of another conducting layer of aprinted circuit board that provides outputs with power from one ofseveral power inputs according to an exemplary embodiment;

FIG. 9 illustrates conducting material of yet another conducting layerof a printed circuit board that provides outputs with power from one ofseveral power inputs according to an exemplary embodiment;

FIG. 10 is an illustration of a group of outputs and associated printedcircuit board that provides outputs with power from different inputsaccording to another exemplary embodiment; and

FIG. 11 is a flow chart illustration of a method for providing powerfrom multiple inputs to adjacent outputs in a PDU.

DETAILED DESCRIPTION

Embodiments of polyphase or multiple input power distribution,monitoring, and management devices, systems and methods are describedherein. Embodiments of such devices and systems include a powerdistribution unit (PDU) with adjacent power outlets being provided withpower from different power inputs through a power distribution printedcircuit board. The present disclosure recognizes that properly balancingloads on different phases of a polyphase PDU is an important task thatis complicated by different phases of power being traditionally providedto different groupings of outputs. Such different groups of outlets aregenerally located along the length of a PDU enclosure, and thus whenadjacent components mounted in an equipment rack are required to beplugged into different phases, their respective power cables may need tobe routed in non-ideal directions. Furthermore, in some cases cablemanagement becomes a challenge due to excessive cable lengths and havingto route cables to different outlet groups. The present disclosureprovides groupings of outlets in which adjacent outlets are connected todifferent power phases. Traditionally, to provide adjacent outlets withpower from different phases, separate physical wires would be requiredto be connected to the adjacent outlets. In cases where a relativelylarge number of outlets are present, such an assembly would requiredozens of connection points each requiring manual connection duringassembly. This would require a very labor intensive process to assemblethe apparatus, with a corresponding increase in likelihood ofmanufacturing errors such as missed or improper connections, shortedconnections, and/or resistive connections which can result in increasedpower usage and decreased reliability, not to mention the added costsattendant with such a configuration.

Embodiments of the present disclosure provide power to outlets through apower distribution printed circuit board interconnected to each powerinput phase. The circuit board allows for the provision of connection ofdifferent power input phases to adjacent outlets. The printed circuitboard includes a number of layers of conductive material, with differentlayers connected to different input inputs or phases and to the linepower connection of different power outlets. Such a printed circuitboard provides a PDU that is significantly easier to manufacture andsignificantly more reliable relative to individual wired connections toeach power outlet from different power inputs or phases.

With reference to FIG. 1, an exemplary power distribution unit (PDU) 100is described. The PDU 100 includes a housing 105 that is configured tobe mounted vertically into an electronic equipment rack. As is wellunderstood, such a vertically mountable PDU 100 may be mounted into anequipment rack at a rear portion of the equipment rack, thus consumingno vertical space in the equipment rack (“zero U”) that would otherwisebe used for computing equipment. The PDU 100 location at the back of theequipment rack allows power cords extending from the rear of thecomputing equipment to be conveniently plugged into the PDU 100. While avertically mountable PDU 100 is illustrated in FIG. 1, the concepts andfeatures described herein may be incorporated into power distributiondevices having other form factors, such as horizontally mountable powerdistribution units, and power distribution devices for use in otherapplications. Accordingly, the particular devices and applicationsdiscussed herein are for representative purposes only.

A power input 110 penetrates the PDU housing 105 and may receive powerinput from multiple power phases, such as a three-phase power input. Inother embodiments, power distribution units may include separate powerinputs that each receive power from a different power source or powerphase. The PDU 100 includes three groups, or banks, of power outlets115, 120, 125, in this embodiment. Each group of power outlets 115, 120,125, includes a number of individual power outlets such as power outputs115-a, 115-b, and 115-c of power outlet group 115, power outlets 120-a,120-b, and 120-c of power outlet group 120, and power outlets 125-a,125-b, and 125-c of power outlet group 125. Individual power outlets115-a, 115-b, and 115-c, are located adjacent to each other and in thisembodiment are each interconnected to a different phase of the threephase power from power input 110. Similarly, power outlets 120-a, 120-b,120-c, and 125-a, 125-b, 125-c, are located adjacent to each other andare each interconnected to a different phase of the three phase powerfrom power input 110. Thus, adjacent outlets within a group of outlets115, 120, 125, are connected to different phases of input power, therebyproviding the capability to have components within an equipment rackthat are directly located above or below one another to be plugged intopower outlets having different power phases without having to route thepower cord for the equipment to different groups or banks of outlets.Such a configuration provides for more convenient load balancing in athree phase system. Furthermore, cable management is simplified throughproviding different power inputs or phases within each outlet groupalong the length of a PDU.

The PDU 100 of this embodiment also includes a display 130 that mayprovide a visual display of information related to the current beingprovided through each of the phases or inputs of power to the PDU 100.Display 130 is preferably a digital display and may be numeric,alphabetic, pictorial, to name a few, or a combination of the foregoing,without limitation. In the embodiment of FIG. 1, the display 130includes three separate displays, one for each input power phase, thusproviding a real-time visual display of current for each phase that mayassist in the balancing of loads on each of the input power phases. Insome embodiments, each phase of power is provided as a separate powerbranch that has an associated circuit protection device, such as acircuit breaker or fuse. The display may also assist in determining thecurrent level for each power phase or branch with respect to a maximumcurrent level that the particular circuit or branch may be operated atwithout blowing a fuse or tripping a circuit breaker. The display 130may also display other power related information, such as the voltage onrespective phases, apparent power (measured in volt-amperes) beingprovided to each phase or branch, active, or real, power (measured inWatts) being provided to each phase or branch, and/or a power factorassociated with each phase or branch, for example. The display 130 mayinclude one or more seven segment LED displays, one or more LCDdisplays, or one or more touch screen displays, for example, thatprovide such power related information regarding each phase, branch,and/or power input. Such a display 130 however is not a requirement, andis therefore not present in various embodiments.

PDU 100 may be useable in a computer network, and may communicate overthe computer network with a communications module 135. Communicationsmodule 135 in various embodiments communicates with a network powermanager that may reside in a workstation or other remote device that isused in the management of a data center or other enterprise managementsystem. The communications module 135 may include a network interfacecard (NIC) that has application firmware and hardware that interfaces tonetwork the PDU 100 with the computer network. The communications module135 may also be connected to one or more environmental sensors, and/orto one or more other PDUs. Similarly as with the display 130, acommunications module is not required, and is not present in variousembodiments.

The PDU 100 may include outlets 115, 120, 125, that are switchable tocontrol the application of power from the input power to a correspondingpower output. The PDU 100 may also provide power state sensing and/orload-sensing with respect to the corresponding power outlets. In someembodiments, load sensing information for the different inputs and/oroutlets is reported over a network through a communications module 135as described above.

With reference now to FIG. 2, a group of outlets 200 is illustrated. Thegroup of outlets 200 in this embodiment are arranged in a modularfashion, and may be referred to as an intelligent power module. In theembodiment of FIG. 2, various circuitry associated with the poweroutlets are contained on a number of interconnected printed circuitboards. In this embodiment, power from the power inputs is provided topower outlets 115-a, 115-b, 115-c through a lower printed circuit board205. The first (lower) circuit board 205 is constructed to provideadjacent outlets 115-a, 115-b, and 115-c with power from different powerinputs or phases. The construction of lower circuit board 205 will bedescribed in more detail below. A second (middle) circuit board 210 anda third (upper) circuit board 215 are interconnected to lower circuitboard 205. In this embodiment upper circuit board 215 includes aplurality of power control relays 220 that work to control theapplication of power to an associated output 115-a, 115-b, 115-c. In theembodiment of FIG. 2, the middle circuit board 210 includes powersensing components that sense and report power-related informationassociated with each power output 115-a, 115-b, 115-c, including currentsensing transformers 225 for each output in this embodiment. Theelectrical connections of each of the circuit boards may be designedsuch that the boards may be assembled with related inputs/outlets andconnections that are aligned so as to provide for efficient modularassembly of power outlet modules that incorporate some or all of thefeatures described herein through the addition of one or more relatedprinted circuit boards.

In various embodiments, the middle and upper circuit boards 210, 215,may not be present, depending upon the particular application of thePDU. In other embodiments, one or more of middle and upper circuitboards 210, 215, are present, depending upon the particular applicationof the PDU. In other embodiments, various different components of anoutlet module 200 may be assembled onto the separate circuit boards thatare then assembled into a power outlet module. In such a manner,component boards may be assembled to include features that are orderedby a particular customer or user of a PDU in which the outlet modulewill be used. Furthermore, a user or customer may desire some, but notall, of the outlets in a PDU to have one or more functions, such asswitching and current reporting, and thus different outlet modules, orsubsets of outlets in an outlet module, may be assembled with theadditional component boards to provide such capability. Such aconfiguration provides flexible and efficient manufacturing optionswhile maintaining high reliability.

In one embodiment, the power outlet module 200 includes eight outlets300, each of IEC-C13 type, such as illustrated in FIG. 3. In thisembodiment, each outlet 300 is a “snap-in” type of outlet that includesa line connector 315, a neutral connector 305, and a ground connector310. The outlets 300 are assembled into the module housing with theoutlet connectors 305, 310, 315 connecting with corresponding openingsin lower printed circuit board 205. Thus the module 200 may be assembledin a relatively efficient and reliable manner. It will be understoodthat this embodiment, and other embodiments described herein as havingIEC-C13 type outlets, are exemplary only and that any of various othertypes of outlets alternatively can be used. For example, the “outlets”can be other NEMA types (e.g., NEMA 5-15R, NEMA 6-20R, NEMA 6-30R orNEMA 6-50R) or any of various IEC types (e.g., IEC C19). It also will beunderstood that all the “outlets” in a particular power outlet module200, or other outlet modules, need not be identical. It also will beunderstood that the “outlets” are not limited to three-prongreceptacles; alternatively, one or more of the “outlets” can beconfigured for two or more than three prongs in the mating maleconnector. It also will be understood that the “outlets” are not limitedto having female prong receptacles. Further, while outlet module 200 ofthis embodiment includes eight outlets, it will be understood that thisis but one example and that an outlet module may include a differentnumber of outlets.

Lower circuit board 205, as mentioned above, provides power to each ofthe power outputs, such as outlets 300. With reference now to FIG. 4, alower circuit board 400 according to an embodiment is described in moredetail. In this embodiment, board 400 includes power inputs for eachpower phase in a three phase power input, the three phases referred toas phase X, phase Y, and phase Z. A first input 402 is connectable tothe phase X input, a second input 405 is connectable to the phase Yinput, and a third input 410 is connectable to the phase Z input. Afourth input 415 is connectable to a neutral line. The circuit board 400also includes inputs 420 connectable to a ground connection. The circuitboard 400 includes a number of sets of connectors 425, 430, 435, thatare spaced and sized to receive connectors 305, 310, and 315 of anoutlet 300. For example, connector set 425 includes a line connection425-a that is arranged to receive line connector 315 of outlet 300, aneutral connection 425-b that is arranged to receive neutral connector305 of outlet 300, and a ground connector 425-c that is arranged toreceive ground connector 310 of outlet 300. In this embodiment, eachline connector 425-a, 430-a, and 435-a connects to a different phase ofpower input, with line connector 425-a connected to phase X, connector430-a connected to phase Y, and connector 430-a connected to phase Z.Thus, adjacent power outputs are connected to a different power input.Using a printed circuit board 400 to achieve such connectionssignificantly reduces the manufacturing complexity of providing such aPDU, as compared to a PDU in which individual wires would be connectedto each adjacent power output.

Using printed circuit board 400 also provides enhanced reliability ascompared to individual wire connections, due to more reliableconnections between outlet 300 and printed circuit board 400. As isunderstood, when connections between power supplying components are notproperly connected, such as through loose mating discrete wireconnectors and/or improper crimping of wires, the connection may haveadditional resistance, and is referred to as an ohmic connection. Ohmicconnections can provide significant reliability and safety issues, dueto heating of such connections and a significantly higher likelihood offailure due to the heating. Using a printed circuit board 400, such asdescribed, significantly reduces the likelihood of such problematicconnections.

As described, board 400 includes connections for nine outlets 300. Inthis manner, three outlets are connected to each phase in an alternatingfashion, namely a first outlet connected to phase X, a second outletconnected to phase Y, a third outlet connected to phase Z, and so onthrough the ninth outlet. In other embodiments, different numbers ofoutputs may be present, such as printed circuit board 500 illustrated inFIG. 5. Such a printed circuit board 500 contains similar connections asprinted circuit board 400, and simply has a reduced number of outputs.

In some embodiments, each power input phase has an associated circuitprotection device, such as a circuit breaker or fuse. In someembodiments, all of the outlets and circuit protection devicesassociated with a particular power phase are color coded on the housingof the PDU. Thus, all of the outlets and circuit protection deviceassociated with phase X may have a first color, all of the outlets andcircuit protection device associated with phase Y may have a secondcolor, and all of the outlets and circuit protection device associatedwith phase Z may have a third color. In such a manner, a particularoutlet and/or circuit protection device may be easily identified withthe corresponding power phase. Similarly, in embodiments that include adisplay, the display may include corresponding color coding to identifythe particular power phase for which power-related information is beingdisplayed. In other embodiments, different numbers of phases or powerinputs may be supplied to the PDU, with corresponding changes to theprinted circuit boards and/or color coding that will be readily apparentto one of skill in the art.

With reference now to FIG. 6, a representation of a circuit board 600 ofan embodiment is discussed. The circuit board 600 (not to scale) isillustrated partially in cross-section and illustrates the number oflayers that are present in the printed circuit board 600. Such aconstruction may be used in circuit boards 205, 400 and 500, forexample. The printed circuit board 600 is made of a number ofalternating layers of conductors and insulators. The circuit board 600is fabricated to have a number of interleaved conducting and insulatinglayers, with the various conducting layers in facing relationship toother of the conducting layers and thereby forming a circuit board 600having a compact sandwiched-type configuration of alternating conductingand insulating layers. A top layer 605 in this embodiment includes bothconductors and insulative material that provides circuit connections andelectrical insulation, and a protective coating for the printed circuitboard 600. A first insulating layer 610 is located beneath the top layer605, and provides electrical insulation between the top layer and firstconducting layer 615. The first inner conducting layer 615, in thisembodiment, includes three electrically insulated conductive portions,one of which is connected to the phase input corresponding to phase Xand the other two that are ground connections. A second insulating layer620 is located beneath the first conducting layer 615, and provideselectrical insulation between the first conducting layer and secondconducting layer 625. The second inner conducting layer 625, in thisembodiment, includes three electrically insulated conductive portions,one of which is connected to the phase input corresponding to phase Yand the other two that are ground connections. A third insulating layer630 is located beneath the second conducting layer 625 and provideselectrical insulation between the second conducting layer 625 and thirdconducting layer 635. The third inner conducting layer 635 in thisembodiment includes three electrically insulated conductive portions,one of which is connected to the phase input corresponding to phase Zand the other two are ground connections. A fourth insulating layer 640is located beneath the third conducting layer 635 and provideselectrical insulation between the third conducting layer 635 and fourthconducting layer 645. The fourth inner conducting layer 645 in thisembodiment is connected to the neutral input. A fifth insulating layer650 is located beneath the fourth conducting layer 645 and provideselectrical insulation between the fourth conducting layer 645 and abottom layer 655. The bottom layer 655 in this embodiment includes bothconductors and insulative material that provides circuit connections andelectrical insulation, and a protective coating for the printed circuitboard 600. The printed circuit board 600 also has a plurality ofconductively plated through holes that correspond to a line connection425-a that is arranged to receive line connector 315 of outlet 300, aneutral connection 425-b that is arranged to receive neutral connector305 of outlet 300, and a ground connector 425-c that is arranged toreceive ground connector 310 of outlet 300. As will be readilyunderstood, the circuit board 600 includes conductively plated throughholes that correspond to other outlets.

The conductive layers 605, 615, 625, 635, 645, and 655 include voids inconductive material, such as copper, around through holes that are notto be electrically connected to the particular conductive layer. FIGS.7-9 illustrate different conductive layers 615 (FIG. 7), 625 (FIGS. 8),and 635 (FIG. 9). Taking conductive layer 615 of FIG. 7 as an example,the conductive layer of this embodiment includes a copper conductor,denoted by the light areas, and voids in conductor material denoted bydark areas of FIG. 7. The voids are placed such that the conductivelayer 615 does not contact the plated through holes corresponding tooutputs that are not to be connected to the particular phase input ofthe conducting layer. Thus, in the example of FIG. 7, conductivematerial is present at the input 410 for the polyphase phase Z input,and at the line connection 425-a of the output 425. The layer 615includes voids around the line connections 430-a and 435-a of outputs430 and 435, respectively. In this manner, the conductively platedthrough hole associated with line connection 425-a is electricallyconnected to the phase Z input 410, while the line connections 430-a and435-a of outputs 430 and 435 are electrically insulated from the phase Yinput 402. Conducting layer 615 includes a line side and a ground sides,that are electrically insulated. The ground side of layer 615 hasconductive material present at the ground connections for each of theoutputs, and has voids associated with the through holes correspondingto the neutral connections of each output. FIG. 8 illustrates conductivelayer 625 and connections to the phase Y input in a similar manner. FIG.9 illustrates conductive layer 635 and connections to the phase X inputin a similar manner.

While the embodiments of FIGS. 4-9 illustrate multiple power phaseconnections in a “wye” type configuration, where outputs are connectedbetween a particular power phase and a neutral line, similarconstructions may be used to provide outputs that are connected tomultiple power phases in a “delta” type configuration. In suchembodiments, the conducting layers for different power phase inputs aresimply extended to overlap with both of the non-ground power inputs of acorresponding power output. The conducting layers corresponding to thedifferent power phases are provided with corresponding electricalinsulation (such as through above-described voids) and connections toconductively plated through holes for the power output connections.Thus, the conductively plated through holes for a particular poweroutput may be selectively connected to the two appropriate input powerphases to provide a power output that is connected phase-to-phase,rather than phase-to-neutral.

Accordingly, described are printed circuit boards that may be used toprovide adjacent power outputs with power from different power inputswithout requiring complex wiring harnesses and a large number ofindividual wired connections. Outlets, such as outlet 300 of FIG. 3, mayhave connectors inserted into corresponding through holes in theexemplary printed circuit boards and be electrically connected to theappropriate electrical connections. Of course, the concepts of theprinted circuit boards described herein may be applied to printedcircuit boards that also include other components as well. FIG. 10illustrates an example of a printed circuit board 966 that incorporatesthe multiple conductive layers as described above, to provide adjacentoutlets 950 with power from different power inputs. In this embodiment,the line power is provided to outlets 950 through a line connection 954that is routed through a relay 958 and an associated current transformer962. The relays 958 and current transformers 962 are interconnected tocontrol and monitoring circuitry such as described above. In thisembodiment, the printed circuit board 966 is mounted at a 90 degreeangle relative to the plane of the outlets 950. In this manner, theadditional surface area required by the circuit board 966 is provided ina plane that is generally perpendicular to the plane of the outlets 950,rather than in a parallel plane as illustrated in the embodiment of FIG.2. By configuring the circuit board 966 perpendicular to the plane ofthe outlets 950, this additional surface area can be accommodated simplybe making the PDU housing somewhat deeper, with the width of the housingremaining substantially the same as the embodiment of FIG. 1. Using asingle printed circuit board 966 allows a reduced manufacturing cost andprovides efficiencies in manufacturing due to reduced assembly stepsrelative to embodiments with more than one printed circuit board.

As noted in several of the above-described embodiments, power frommultiple inputs may be distributed through a printed circuit board thatis fabricated with interspersed or interleaved conductive and insulatinglayers in a sandwiched relationship to have the characteristicsdiscussed in the above embodiments. With reference now to FIG. 11, aflow chart illustration of an exemplary method 1100 for providing powerto adjacent power outputs from different power inputs in a powerdistribution unit is described, which may employ such a sandwichedprinted circuit board. In this embodiment, as noted at block 1105, afirst conducting layer of a printed circuit board is connected to afirst power input. At block 1110, a second conducting layer of theprinted circuit board is connected to a second power input. The secondconducting layer in various embodiments is located at least partiallyabove the first conducting layer in a facing relationship thereto, andis electrically insulated from the first conducting layer. A line powerconnection of a first power outlet is connected to the first conductinglayer, according to block 1115. A line power connection of a secondpower outlet adjacent to the first power outlet is connected to thesecond conducting layer, as noted at block 1120. A third conductinglayer of the printed circuit board is connected to a third power inputat block 1125. Similarly as above, the third conducting layer is locatedat least partially above the first and second conducting layers andelectrically insulated from the first and second conducting layers. Atblock 1130 a line power connection of a third power outlet adjacent toone of the first and second power outlets is connected to the thirdconducting layer. According to some embodiments, connecting the linepower connection of the first power outlet to the first conducting layercomprises connecting a first conductively plated through hole to theline power connection of the first power output, the first conductivelyplated though hole extending through the first and second conductinglayers, electrically connected to the first conducting layer, andelectrically insulated from the second conducting layer. Similarly, theconnecting a line power connection of the second and third power outletsto the second and third conducting layers may comprise, respectively,connecting second and third conductively plated through holes to theline power connection of the second and third power outlets. The secondand third conductively plated though holes extending through each of theconducting layers and being electrically connected to the second andthird conducting layers, respectively. Each conductively plated throughhole is electrically insulated from the other conducting layers, in amanner similarly as described above. Of course, it will be readilyrecognized that the steps of method 1100 are exemplary in nature, andnumerous variations of the order of steps, additional stems, of fewersteps, may be present in various embodiments. For example, if power fromdual power inputs is desired to be connected to alternating adjacentpower outlets in a PDU, the sandwiched printed circuit board may includeconducting layers for each of the dual power inputs, with line powerconnections of adjacent outlets connected to the appropriate conductinglayers.

As will be readily recognized from the above described embodiments, thepresent disclosure provides efficient and reliable output of power frommultiple power inputs to adjacent power outputs. It can thus be seenthat the foregoing and other embodiments, or aspects thereof, canvariously provide one or more among the following problem solutions,advantages, or benefits:

-   -   efficient manufacturing and assembly of power distribution units        having groups of linearly arranged power outlet with adjacent        power outputs connected to different power sources;    -   lower cost PDUs having the above-described features through        reduction of materials required to manufacture and assemble such        PDUs;    -   lower cost PDUs having the above-described features through        reduction of assembly steps required to assemble such PDUs;    -   PDUs having higher reliability due to reduced likelihood of        manufacturing errors and/or resistive connections between        adjacent outlets having different power source inputs;    -   efficient load balancing between phases of polyphase PDUs;    -   in dual input PDUs, equipment having internal redundant power        supplies requiring connection to redundant power sources may be        connected to adjacent outlets in a PDU, simplifying cable        management;    -   PDUs with multiple groups of power outlets with options for        connecting adjacent components in an equipment rack to adjacent        outputs of the PDU, rather than to outlets in different outlet        groups, thereby simplifying cable management; and    -   PDUs having one or more of the above-noted features in a compact        form factor that consumes zero units of equipment rack space.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Throughout this disclosure the term “example” or“exemplary” indicates an example or instance and does not imply orrequire any preference for the noted example. Thus, the disclosure isnot to be limited to the examples and designs described herein but is tobe accorded the widest scope consistent with the principles and novelfeatures disclosed herein.

We claim:
 1. A power distribution apparatus comprising: a powerdistribution unit housing; at least one power input disposed at leastpartially within the housing comprising at least a first input line anda second input line; and at least one outlet comprising at least aprimary connector and a secondary connector; at least one printedcircuit board disposed in the housing comprising at least two conductinglayers, at least one of the two conducting layers comprising at least afirst conducting region and a second conducting region, wherein thefirst conducting region is electrically interconnected to the firstinput line and the primary connector, and the second conducting regionis electrically insulated from the first conducting region andelectrically interconnected to the second input line and the secondaryconnector.
 2. The apparatus of claim 1, further comprising: a pluralityof power control relays disposed in the housing, each power controlrelay being connected in independent power controlling communicationbetween the at least one power input and the at least one outlet.
 3. Theapparatus of claim 1, further comprising: a current-related informationreporting system disposed at least partially in the housing incurrent-related information determining communication with the at leastone outlet, the at least one power input, or a combination thereof, andconnectable in current-related information transfer communication with aseparate communications network distal from the power distributionapparatus.
 4. The apparatus of claim 1, wherein the at least one powerinput comprises multiple power phase inputs connectable to differentrespective power sources.
 5. The apparatus of claim 1, wherein the atleast one power input comprises a three phase power input.
 6. A powerdistribution apparatus comprising: a power distribution unit housing; atleast one power input disposed at least partially within the housingcomprising a plurality of input lines, wherein the at least one powerinput is electrically connectable to at least two different powersources; a plurality of outlets comprising at least a first outlet and asecond outlet located adjacent to the first outlet; at least one printedcircuit board disposed in the housing comprising: (i) a first conductinglayer electrically interconnected with at least a first input line ofthe plurality of input lines and electrically interconnected with thefirst outlet, (ii) a second conducting layer located at least partiallyabove the first conducting layer and in facing relationship thereto,electrically insulated from the first conducting layer, electricallyinterconnected with at least a second input line of the plurality ofinput lines, and electrically interconnected with the second outlet,wherein at least one of the first conducting layer and the secondconducting layer includes at least a first conducting region and asecond conducting region, the first conducting region being electricallyinsulated from the second conducting region, and the first and secondconducting regions being electrically interconnected with differentinput lines of the plurality of input lines.
 7. The apparatus of claim6, further comprising: a plurality of power control relays disposed inthe housing, each power control relay being connected in independentpower controlling communication between the at least one power input andat least one of the plurality of outlets.
 8. The apparatus of claim 6,further comprising: a current-related information reporting systemdisposed in the housing in current-related information determiningcommunication with one or more of the plurality of outlets, the powerinput, or a combination thereof, and connectable in current-relatedinformation transfer communication with a separate communicationsnetwork distal from the power distribution apparatus.
 9. The apparatusof claim 6, wherein the at least one power input comprises a three phasepower input.
 10. The apparatus of claim 6, wherein the printed circuitboard further comprises a first conductively plated through holeextending through the first and second conducting layers, electricallyconnected to the first conducting layer, electrically insulated from thesecond conducting layer, and electrically interconnected to the firstoutlet.
 11. The apparatus of claim 10, wherein the printed circuit boardfurther comprises a second conductively plated through hole extendingthrough the first and second conducting layers, electrically connectedto the second conducting layer, electrically insulated from the firstconducting layer, and electrically interconnected to the second outlet.12. The apparatus of claim 6, wherein the plurality of outlets furthercomprises a third outlet located adjacent to the second outlet, andwherein the printed circuit board further comprises: (iii) a thirdconducting layer located at least partially above the first and secondconducting layers, electrically insulated from the first and secondconducting layers, electrically interconnected with at least a thirdinput line of the plurality of input lines, and electricallyinterconnected with the third outlet.
 13. The apparatus of claim 12,wherein the printed circuit board further comprises: a firstconductively plated through hole extending through the first, second,and third conducting layers, electrically connected to the firstconducting layer, electrically insulated from the second and thirdconducting layers, and electrically interconnected to the first outlet;a second conductively plated through hole extending through the first,second, and third conducting layers, electrically connected to thesecond conducting layer, electrically insulated from the first and thirdconducting layers, and electrically interconnected to the second outlet;a third conductively plated through hole extending through the first,second, and third conducting layers, electrically connected to the thirdconducting layer, electrically insulated from the first and secondconducting layers, and electrically interconnected to the third outlet.14. The apparatus of claim 6, wherein the plurality of outlets comprisesat least first and second groups of linearly arranged outlets, adjacentoutlets in each of the groups being electrically interconnected todifferent power sources.
 15. A printed circuit board apparatus forproviding adjacent power outputs with power from different power inputs,comprising: a first conducting layer comprising a first input connectionconfigured to be connected to at least a first input line of a pluralityof input lines and a first output connection configured to be connectedto a first power output; and a second conducting layer located at leastpartially above the first conducting layer and electrically insulatedfrom the first conducting layer, comprising a second input connectionconfigured to be connected to at least a second input line of theplurality of input lines and a second output connection configured to beconnected to a second power output, wherein at least one of the firstconducting layer and the second conducting layer includes at least afirst conducting region and a second conducting region, the firstconducting region being electrically insulated from the secondconducting region, and the first and second conducting regions beingelectrically interconnected to different input lines of the plurality ofinput lines.
 16. The apparatus of claim 15, further comprising a firstconductively plated through hole extending through the first and secondconducting layers, electrically connected to the first conducting layer,and electrically insulated from the second conducting layer.
 17. Theapparatus of claim 16, further comprising a second conductively platedthrough hole extending through the first and second conducting layers,electrically connected to the second conducting layer, and electricallyinsulated from the first conducting layer.
 18. The apparatus of claim16, wherein a first insulating layer is interleaved with the first andsecond conducting layers, and wherein the first conducting layer, firstinsulating layer, and second conducting layer are in a sandwichedconfiguration.
 19. The apparatus of claim 15, further comprising a thirdconducting layer located at least partially above the first and secondconducting layers, electrically insulated from the first and secondconducting layers, comprising a third input connection configured to beconnected to at least a third input line of the plurality of input linesand third output connection configured to be connected to a third poweroutput.
 20. The apparatus of claim 19, wherein the printed circuit boardfurther comprises: a first conductively plated through hole extendingthrough the first, second, and third conducting layers, electricallyconnected to the first conducting layer, electrically insulated from thesecond and third conducting layers, and electrically interconnected to afirst power output connection; a second conductively plated through holeextending through the first, second, and third conducting layers,electrically connected to the second conducting layer, electricallyinsulated from the first and third conducting layers, and electricallyinterconnected to a second power output connection; a third conductivelyplated through hole extending through the first, second, and thirdconducting layers, electrically connected to the third conducting layer,electrically insulated from the first and second conducting layers, andelectrically interconnected to a third power output connection.